<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
    <title>Title</title>
</head>
<body>
<style>
    .p{
        font-size: 50px;
        color: #9C1A1C;
    }
    .h{
        font-size: 100px;
        color: red;
    }
</style>
<input type="button" value="test" id="buttn1">
<div id="div1" style="display: none">
    <p id="p">
    hello
</p>
<h1 id="h">
    AAA
</h1>

</div>
<div id="div1">
 <label>chs</label>
    <input type="button" onclick="f()">
    <input type="checkbox" value="1" id="op">
    <input type="checkbox" value="2" id="op">
    <input type="checkbox" value="3" id="op">
    <input type="checkbox" value="4" id="op">
    <script type="application/javascript">
        function f() {
            alert("test");
        const op = document.getElementById('op');
        console.log(op);
        for (let i=0;i<op.length;i++){
            if (op[i].checked)
                alert(op[i].value);
                console.log(op[i]);
                console.log(op[i].value);
        }
        }
    </script>
{#    <select id="se1" onchange="f()">#}
{#        <option id=op value="3">3</option>#}
{#        <option id=op value="2">2</option>#}
{#        <option id=op value="1">1</option>#}
{#    </select>#}
{#</div>#}
{#<script type="application/javascript">#}
{#    const op = document.getElementById('op');#}
{##}
{#</script>#}
{#<script type="application/javascript">#}
{#    function f() {#}
{#    const div1 = document.getElementById('div1');#}
{#    const p= document.getElementById('p');#}
{#    const h= document.getElementById('h');#}
{#    const button = document.getElementById('buttn1')#}
{#    button.onclick = function () {#}
{#      p.className ='p';#}
{#      h.className = 'h';#}
{#      div1.style.display='inline';#}
{#      div1.innerHTML = '<h3 id="h" class="h">hello111</h3>'#}
{#    const se1 = document.getElementById('se1'); //��ȡ select ��IDֵ#}
{#    se1.options.add(new Option("op1","999"));#}
{#    const sev = document.getElementById('se1').value;#}
{#    console.log(sev);#}
{#    }#}
{#    function chs() {#}
{#    const sev = document.getElementById('se1').value;#}
{#    console.log(sev);#}
{#    }#}
{#    }#}
{#</script>#}
</body>
</html>